You can't enable the driver in YOU, only download it. Yast will then install this itself. You don't need to do anything else. You don't need to run Sax2, you don't need to update the XF86Config file. It is all done for you.

If you select graphics card from within Yast, it will load up Sax. If you try and toggle the switch, enable 3D acceleation Sax2 will put up an error message stating that since Suse8.2 the 3D drivers are no longer shipped with Suse linux since licensing restrictions don't allow it. It will deselect the toggle switch.

If you don't want to use Yast Online Update and do it the hardway, you need to download the 5336 drivers from Nvidias website. Download their readme file and down the suse-nvidia howto document. Follow the instructions they have precisely and you will have a 3D accelerated X server. Don't follow theire instructions and you will be stuck with a 2D server.